Hi,
Oops, I didn't know about the option. It's running with GDI. But just replacing the DDraw library sped it up. Probably depth conversion? OpenGL don't work.
Hmm. No idea. SURFACE_GDI should be as fast as the old ddraw code, the rendering is the same.
There is a registry key, HKLU\software\wine\direct3d\DirectDrawRenderer. It can be set to "gdi" to force gdi surfaces, or "opengl" to force opengl surfaces. If "gdi" is set, Direct3D is mutually disabled.
But still it is interesting that it is faster...